Reports: Windows 10 Mobile eating up data plans even when WiFi is available

Windows 10 Mobile is still a fresh mobile OS. It has only been released with brand new phones so far, and has yet to be released as an upgrade for older devices. It almost goes without saying that brand new OS’s generally have their bugs. Apple had annoying problems with apps crashing and devices not working right after the release of iOS 8. But such problems were inconveniences. Now it appears Windows 10 Mobile has a serious enough bug that is more than just an inconvenience, it could actually hit your wallet.

Windows Insiders took to Reddit to look for help with a big problem with Windows 10 Mobile Insider Previews. Some users are reporting that the OS is “eating my data plan.” Reddit user ninjanijav stated “System” on his Lumia 830 running the latest Insider Build had used up 3GB of cellular data even when connected to WiFi. Other users are saying that “System” will consume hundreds of MBs a day, which quickly adds up.

Other users were quick to offer help as it appears the culprit is the SMS and MMS back up feature in Windows 10 Mobile. It seems Windows 10 Mobile is eating up GB’s of cellular data when the phone is restoring backups of years’ worth of text messages. The problem is the “feature” is using cellular data even when it has a WiFi connection available. Having an errant app needlessly consume cellular data can be a pricey bug as data overages for most cellular plans can be quite expensive compared to the monthly cost of a normal data plan.

To see if your phone is needlessly eating up huge amounts of data head over to Settings. From the Settings menu go to Network & Wireless > Data usage. Then click Usage details to get the breakdown of how much data each app has used up. “System” is usually at the bottom of the list. The app usage for “System” can also be a high number because of App and phone backups which occur over WiFi. But if your Data usage report shows an unusually high amount of cellular data consumption, “System” might be the culprit.

If “System” is draining a huge amount of your monthly metered data, there is a way to stop it. Reddit user hulkulesenstein found that simply disabling the auto-backup/restore feature stemmed the tide of bleeding cellular data. To do this go Settings > System > Messaging and then toggle Sync messages between devices. The other last resorts are to disable your cellular connection or to roll back to Windows Phone 8.1.

With Windows 10 Mobile yet to roll out to older devices, this latest bug in the Insider Preview build that can hit you in your wallet could be one of the factors holding up a general release. Hopefully, it is a quick fix. A MSFTChamp did speak up in Reddit saying the “Data team is actively investigating” the issue, and encourages users to vote on the issue in the Windows Feedback app.